I used Idye for my ikea slip covers. Six in total. I tried using a modified stove top method. I could not find a large enough pot so I used a very large bucket and poured boiling water into it with the dye.

Once I was finished I washed the slipcovers and they are blotchy also the seams didn't dye.

Went to the Ikea website to check the fabric type on your slipcovers - so am going forward with the assumption that you used iDye for Natural fiber/fabrics. I did notice that the white 'hendriksdal' style suggested that 'Light stains can be removed with a textile cleaner or a damp sponge and a mild soapy solution.' This suggests to me that the fabric might be treated with a stain resistant product and if that is the case would be a big part of the cause of your results. The treatment will have interfered with the the fabric's ability to take the dye. I'd suggest contacting Ikea and checking with them about that - if that is the case sometimes washing in very hot water can remove/reduce that treatment. Again, I'd check with Ikea about that.To try and fix the dye results I'd suggest removing the existing color and then redyeing. Unless you are dyeing a very dark color the blotchyness will translate through the over-dye and give you darker blotches.You will need to use the stove top method for removing the dye, the water does need to reach and maintain 212°F. (This process may help to remove any stain resistance treatment, too.)I also recommend dividing to conquer. Can you get two of the slip covers in a large pot? Dyeing the covers in batches using the stove top method is going to give you best results. You'll want to be sure to use the same amount of dye for the same amount of covers and get as close as possible to the same amount of water in the dye pot and you should have very good results. I do recommend dissolving the dye packet in 4 cups of warm water and measuring from that solution for your dye bath - much easier to handle the liquid vs the powder. If you are having trouble finding something local to you we have large pots available: http://www.jacquardproducts.com/closeouts1.htmlAbout the seams: if you are referring to the stitching on the seams, there is a good possibility that the threads are a poly or acrylic fiber and will not dye with the iDye for Natural fibers. If the area around the seams didn't take the dye or took it at a lesser rate I'd say that was a result of the extra layers of fabric in that area and the resistance that stitching creates (a couple of layers of fabric tightly bound to each other makes it more difficult for the dye to penetrate), using the stove top method will reduce/remove that problem as the heat helps the dye penetrate. Making sure you use the salt will help with that, too.

Hope this helps some, don't hesitate to ask if you have more questions.annette